kspkit: KSP frontend for genkit — KSP symbols -> neutral model, reporter and code writer

KAudit KSP2 processor: add with ksp(...) to generate Type.diff() at compile time

KMapX KSP2 processor: add with ksp(...) to generate mappers at compile time

KValid KSP2 processor: add with ksp(...) to generate Type.validate() at compile time